Apparatus and Methods for Enhanced Fluid Delivery on Bevel Etch Applications

ABSTRACT

An apparatus to supply a plurality of process fluids for processing a substrate in a semiconductor processing chamber is disclosed. The apparatus includes a plurality of process fluid supply valves and a fluid supply network that is defined between a crossover valve and a tuning supply valve. The apparatus further includes a tuning fluid supply being connected to the fluid supply network through the tuning supply valve. Further included with the apparatus is a plurality of process fluids that are connected to the fluid supply network through the plurality of process fluid supply valves. A process chamber that has a substrate support is also included in the apparatus. The process chamber further including an edge fluid supply and a center fluid supply, the edge fluid supply connected to the fluid supply network through an edge enable valve and the center supply connected to the fluid supply network through a center enable valve. Wherein the crossover valve, edge enable valve, and center enable valve allow one of tuning fluid or process fluids to flow to one of the edge fluid supply or the center fluid supply.

BACKGROUND

Cleaning operations are becoming more critical during the manufacture ofsemiconductor wafers. Due to the changing nature of the manufacturingoperations and the continuing desire to further reduce feature sizestimely removal of particulate material from semiconductor substrate iscritical. Commensurate with the continued desire for reduced featuresize is the desire to have process equipment that can provideflexibility in order to maximize equipment utilization and minimizedowntime for reconfiguration. Having process equipment that isreconfigurable to perform multiple process operations can reduce thenumber of tools required, thereby potentially decreasing manufacturingand maintenance costs. In addition, as feature size continues todecrease, semiconductor substrates are increasingly sensitive tocontamination.

Accordingly, there is a need to provide a robust fluid delivery systemthat is capable of providing process flexibility for enhanced processperformance while minimizing potential sources of contamination.

SUMMARY

In one embodiment, an apparatus to supply a plurality of process fluidsfor processing a substrate in a semiconductor processing chamber isdisclosed. The apparatus includes a plurality of process fluid supplyvalves and a fluid supply network that is defined between a crossovervalve and a tuning supply valve. The apparatus further includes a tuningfluid supply being connected to the fluid supply network through thetuning supply valve. Further included with the apparatus is a pluralityof process fluids that are connected to the fluid supply network throughthe plurality of process fluid supply valves. A process chamber that hasa substrate support is also included in the apparatus. The processchamber further including an edge fluid supply and a center fluidsupply. The edge fluid supply is connected to the fluid supply networkthrough an edge enable valve and the center supply is connected to thefluid supply network through a center enable valve. The crossover valve,edge enable valve, and center enable valve allow one of tuning fluid orprocess fluids to flow to one of the edge fluid supply or the centerfluid supply.

In another embodiment, a method to provide flexible application of atuning fluid and a process fluid to a substrate is disclosed. The methodincludes operations that enable flow of the tuning fluid to a centersupply through a first supply network. The first supply network iscoupled to a cross-flow network that includes a closed crossflow valve.In another operation process fluid flow is enabled to the edge supplythrough a second supply network, where the second supply network iscoupled to the cross-flow network. In still another operation flow ofthe tuning fluid and the process fluid is disabled. In another operationthe first supply network, the second supply network, the cross-flownetwork, the center supply and the edge supply are purged through apurge network that is connected between the cross-flow network and thecenter supply and edge supply. In another operation flow of the processfluid is enabled, wherein a open cross-flow valve routes the processfluid to the center supply.

Other aspects and advantages of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, illustrating by way of example the principles ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further advantages thereof, may best beunderstood by reference to the following description taken inconjunction with the accompanying drawings.

FIG. 1 shows a simplified exemplary schematic of a fluid supply systemfor a processing chamber for use in semiconductor fabrication, inaccordance with one embodiment of the present invention.

FIG. 2 is an exemplary cross-section view of a chamber, in accordancewith one embodiment of the present invention.

FIG. 3 is an exemplary illustration of a close up of a cross-section ofan edge feed within the chamber in accordance with one embodiment of thepresent invention.

FIG. 4 is an exemplary illustration of a cross-section of a center feedwithin the chamber, in accordance with one embodiment of the presentinvention.

FIG. 5 is an exemplary illustration of valve positions for routing thetuning fluid to the center of the substrate and the process fluids tothe edge of the substrate, in accordance with one embodiment of thepresent invention.

FIG. 6A is an exemplary illustration of valve positions for purging theinput supply network, the crossover supply network and the chambersupply network, in accordance with one embodiment of the presentinvention.

FIG. 6B illustrates an embodiment for the purge of a single process gasin accordance with one embodiment of the invention.

FIG. 6C illustrates an embodiment for the valve positions for thepurging of the supply and tuning lines in accordance with one embodimentof the invention.

FIG. 6D is a simplified schematic diagram illustrating the valvepositions for a chamber vent process in accordance with one embodimentof the invention.

FIG. 7A is an exemplary illustration of valve positions for routing theprocess fluid to the center of the substrate, in accordance with oneembodiment of the present invention.

FIG. 7B illustrates the valve positions for delivering tuning andprocess fluids to an edge of the edge region of a substrate disposed inthe chamber.

FIG. 8 is flow chart with exemplary illustrations for modifying the flowof a tuning fluid and process fluids in accordance with one embodimentof the present invention.

DETAILED DESCRIPTION

An invention is disclosed for providing flexible configuration forsemiconductor processing equipment. The ability to rapidly reconfigure aprocessing chamber provides manufacturers with flexibility regardingthey type of processes that can be performed. This can lead to fasterproduction times and decreased tool downtime for reconfiguration. In oneembodiment, a supply network is disclosed that enables edge etchingprocess fluids to be routed and dispensed near the center of asubstrate. Alternatively, in one embodiment tuning fluids normallydistributed near the center of the substrate may be routed to anddispensed near the edge of the substrate. In still another embodiments,the process fluids can be routed toward the center of the substrate, orthe process fluids can be routed to both the center of the substrate andthe edge of the substrate. The particular examples discussed above areintended to be exemplary and should not be construed as limiting asvarious combinations of these embodiments may be utilized.

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be apparent, however, to one skilled in the art that the presentinvention may be practiced without some or all of these specificdetails. In other instances, well known process steps have not beendescribed in detail in order not to unnecessarily obscure the presentinvention.

FIG. 1 illustrates a simplified exemplary schematic of a fluid supplysystem for a processing chamber 100 for use in semiconductorfabrication, in accordance with one embodiment of the present invention.The processing chamber 100 is configured with a chamber supply network126 that includes an edge supply 126 a and a center supply 126 b.Coupled to the chamber supply network 126 is a crossover network 124.Within the crossover network 124, there is a crossflow valve 116, anedge enable valve 108 and a center enable valve 110. The edge enablevalve 108 and the center enable valve 110 are optional for thisembodiment and should be considered exemplary. Other embodiments mayinclude additional valves within the crossover network 124.

Coupled to the crossover network 124 is a source network 122. In theembodiment illustrated in FIG. 1, the source network 122 includes fivefluid sources G1-G5 although more or fewer fluid sources may be used. Inone embodiment G1 is a tuning fluid such as nitrogen. In otherembodiments G1 can be another fluid such as any suitable inert gas oreven a mixture of inert gases, such as argon, helium, neon, xenon, etc.(The other four fluid sources G2-G5 are process fluids that can becombined in various ratios depending on the processing being performedwithin the chamber 100. For the embodiment shown in FIG. 1, fluidsources G2-G5 can include processing fluids for use in an etchingprocess such as, but not limited to, oxygen (O₂), carbon dioxide (CO₂),tetrafluoromethane (CF₄), sulfur tetrafluoride (SF₄) and SF₆, etc., ormixtures thereof.

The individual fluids G1-G5 can be dispensed individually throughrespective valves V1-V5. In one embodiment, where the chamber 100 isconfigured primarily to perform an edge etch of a semiconductorsubstrate, the tuning fluid is connected to the center supply 126 bthrough the crossover network 124. Likewise, the fluid sources G2-G5 areconnected to the edge supply 126 a. However, the crossover network 124allows the chamber to change configurations, thereby allowing processfluids G2-G5 to be sent to the center supply 126 b. Alternatively, thecrossover network 124 can further allow the tuning fluid to be routed tothe edge supply 126 a.

Coupled to both the source network 122 and the chamber supply network126 are purge valves 112, 114, 118 and 120. The purge valves, inconjunction with additional valves throughout the source network 122,crossover network 124 and chamber supply network 126 enable fluidswithin the source network 122, crossover network 124 and chamber supplynetwork 126 to be purged before changing valve positions within thecrossover network 122. Purging and clearing the respective networksbefore utilizing the crossover network 122 can prevent unwantedreactions that could lead to particle generation within the respectivenetworks. In other embodiments, where the process fluids and tuningfluids are non-reactive with each other, the purging valves may beomitted in order to simplify fabrication and reduce fabrication costs.As illustrated in FIG. 1, pump 101 is in fluid communication with valves112 and 114. In addition pump 101 is in fluid communication with chamber100 through valve 103 for purging the chamber. It should be appreciatedthat the box above valve 103 represents a throttle control valve thatopens and closes to maintain a certain chamber pressure. i.e., thethrottle control valve does not seal.

Regardless of whether a purging system is used, the crossover network124 allows fluid that was sent to the edge supply 126 a to be sent tothe center supply 126 b. One advantage of including the purge valves isthe potential to reduce fluid transition times and improved control overpressure transients during fluid switching processing. The purge valvesallow fluids within the supplies to be quickly evacuated beforeswitching the crossover valve. Thus, the purge valves can allow forfaster transitions times when altering the flow of fluids to the processchamber.

In some embodiments, a separate purge fluid can be used to clear therespective supplies. The ability to have a separate purge fluid from thetuning fluid allows enhanced process control while reducing potentialcontamination issues by means of introducing alternative chemistries tothe center or the edge supplies.

The ability to easily change the configuration of the fluid supplies canprovide flexibility during the processing of semiconductor substrates.For example, the ability to split the flow such that the tuning fluid isdelivered to the center supply 126 b and the process fluid is deliveredto the edge supply 126 a, allows for increased process performance and areduction in potential contamination issues. Furthermore, the ability tochange the configuration of the fluid supplies can reduce the totalnumber of processing chambers required to process a semiconductorsubstrate. Additionally, the ability to route all fluids to the edgesupply 126 a or the center supply 126 b provides flexibility indeveloping new processes with enhanced process performance and reducedcontamination issues.

FIG. 2 is an exemplary cross-section view of a chamber 100, inaccordance with one embodiment of the present invention. Thecross-section illustrates both a center feed 202 and an edge feed 200within the chamber 100. The edge feed 200 is connected to the edgesupply from FIG. 1. Likewise, the center feed 202 is connected to thecenter supply from FIG. 1. Thus, fluids routed to the edge supply ofFIG. 1 are distributed within the chamber 100 by the edge feed 200.Similarly, fluids routed to the center supply of FIG. 1 are distributedwithin the chamber 100 by the center feed 202.

Within the chamber 100, a plate 204 and a top plate 206 are visible.Additionally, the chamber liner 208 is visible. In the embodimentillustrated the center feed 202 and the edge feed 200 enter through thetop of the chamber 100. Visible on top of the chamber 100 are centerisolation valve 106 and edge isolation valve 104. As illustrated, thecenter feed 202 obstructs the view the edge feed 200. In the embodimentshown, the edge feed 200 is located behind the center feed 202.

Furthermore, the edge feed 200 includes a manifold that distributes theedge feed 200 to a plurality of branches that extend radially toward theedge of a substrate. This allows the edge feed 200 to distribute fluidto multiple points around the edge of a substrate within the chamber. Inone embodiment, fluid supplied to the center feed is dispensed through aplurality of ports in order to promote even distribution of the fluidaround the center of the substrate.

FIG. 3 is an exemplary illustration of a close up of a cross-section ofan edge feed 200 within the chamber 100 in accordance with oneembodiment of the present invention. The chamber 100 is shown in aclosed position with a bottom surface of the top plate 206 proximate toa top surface of substrate 300. Also visible is the cross-section of anedge feed 200. The edge feed 200 allows fluid supplied to the edgesupply to flow toward the edge of the substrate 300. Recall that similaredge feeds are distributed around the perimeter of the substrate 300.Such a configuration allows process fluids or a tuning fluid to bedistributed evenly around the substrate.

In one embodiment, process fluids for an etch operation are directed tothe edge feed 200. When the edge of the substrate is exposed to theprocess fluids, material that may have been built up on the edge fromprevious processing operations can be removed through an etch operation.In other embodiments, the processing chamber may be reconfigured so theedge feed 200 supplies a tuning fluid to the edge of a substrate.

FIG. 4 is an exemplary illustration of a cross-section of a center feed202 within the chamber 100, in accordance with one embodiment of thepresent invention. Fluids are supplied to the center feed 202 throughthe center supply. In the embodiment illustrated, a manifold within thechamber distributes the fluid from the center feed 202 over the centerof the substrate 300. The number of distribution ports from the manifoldshould not be considered limiting and other embodiments can have feweror more distribution ports coupled to the center feed 202.

FIG. 5 is an exemplary illustration of valve positions for routing thetuning fluid to the center of the substrate and the process fluids tothe edge of the substrate, in accordance with one embodiment of thepresent invention. In this embodiment flow of the tuning fluid isillustrated with a diagonal fill pattern. The tuning fluid is shownflowing through V1 from the supply G1. Similarly, fluid from suppliesG2, G3, G4 and G5 flow through their respective valves V2, V3, V4 andV5. In this embodiment, purge valves 118 and 120 are closed to promoteflow of the tuning fluid and process fluid to the crossover network 124.

With crossover valve 116 being closed and the edge enable valve 110being open, the tuning fluid enters into the chamber supply 126.Likewise, the edge enable valve 108 is open and the process fluid entersinto the chamber supply 126. Both the edge pumpout valve 112 and thecenter pumpout valve 114 are shown as closed in order to enable fluidflow to the chamber. Lastly, edge isolation valve 104 and centerisolation valve 106 are in an open position to allow fluid to flow intothe chamber. It should be appreciated that if valve V1 is closed thenprocess fluids are supplied to the edge and the tuning fluid is notdelivered to the center region of chamber 100.

FIG. 6A is an exemplary illustration of valve positions for purging theinput supply network, the crossover supply network and the chambersupply network, in accordance with one embodiment of the presentinvention. Purging the entire fluid supply network can be performed toevacuate any residual process fluid or tuning fluid and in the instancewhere all the mass flow controllers are to be changed. As illustrated,the edge pumpout valve 112, the center pumpout valve 114, the centerpurge valve 118 and the edge purge valve 120 are open. Conversely, theedge enable valve 108, the center enable valve 110, and the crossovervalve 116 are shown as closed. This allows the center purge valve 118and the edge purge valve 120 to evacuate any remaining fluid from thecombined input supply network and the crossover supply network.

Similarly, the open edge pumpout 112 and center pumpout 114 along withthe open edge isolation valve 104 and center isolation valve 106 allowfluid within the chamber supply 126 to be evacuated. In anotherembodiment, the edge isolation valve 104 and the center isolation valve106 are closed when the edge pumpout valve 112 and center pumpout valve114 are open. This can assist in preventing and particulate orparticulates trapped within the filters 102 from becoming dislodged andbeing pulled into the respective chamber supply lines. In an alternativeembodiment, the edge enable valve 108 and center enable can be left openthereby allowing both the purge valves 118 and 120 to function inconjunction with the pumpout valves 112 and 114. The embodimentillustrated in FIG. 6A should be construed as exemplary. Otherembodiments may include additional valves to enable or disable fluidflow. For example, hand valves (HV) 1-5 are provided to isolate theprocess fluid supplies G1-G5 in this embodiment. Furthermore, additionalvalve, pumps, recycling lines and supply lines may be necessary toeffectuate proper flow within the system. For the sake of simplicity,such items have been omitted from the drawings.

FIG. 6B illustrates an embodiment for the purge of a single process gasin accordance with one embodiment of the invention. In this embodiment,valve 120 is open, as well as valves V3 108, and 104 to enable thepurging of G3 and the corresponding line. It should be appreciated thatvalve 120 is open and valve 103 is closed for the purge process and whenthe pumpout of chamber 100 occurs valve 120 closes and valve 103 opens.One skilled in the art will appreciate that this embodiment may beemployed for changing a single mass flow controller along thecorresponding line.

FIG. 6C illustrates an embodiment for the valve positions for thepurging of the supply and tuning lines in accordance with one embodimentof the invention. In this embodiment, valves 118 and 120 are open forthe purge process, while valve 103 is closed. For the pump out processvalve 103 is open while valves 118 and 120 are closed. FIG. 6D is asimplified schematic diagram illustrating the valve positions for achamber vent process in accordance with one embodiment of the invention.Valves 118, 110 and 106 are initially open to purge and in oneembodiment, when the chamber pressure reaches a certain pressure valves118, 110 and 106 close. In one exemplary embodiment, when the chamberpressure is greater than or equal to one atmosphere, valves 118, 110,and 106 close.

FIG. 7A is an exemplary illustration of valve positions for routing theprocess fluid to the center of the substrate, in accordance with oneembodiment of the present invention. In this embodiment, the processfluid is shown with a diagonal hatch pattern flowing to both the centerof the substrate. The process fluid is supplied through fluid suppliesG2, G3, G4 and G4. Opening the crossover valve 116 allows the processfluid to crossover from the edge supply 126 a to the center supply 126b. As illustrated, the center enable valve 110 is in the open position.It should be appreciated that if V1 is open then tuning and processfluid is delivered to the center region.

FIG. 7B illustrates the valve positions for delivering tuning andprocess fluids to an edge of the edge region of a substrate disposed inchamber 100. In this embodiment, valves 104, 108 and 116 are open toenable the tuning and process fluids access to the edge region.

FIG. 8 is an exemplary flow chart illustrating procedural operations tomodify the flow of process fluids in accordance with one embodiment ofthe present invention. The procedure is initiated by operation 800,where flow of a tuning fluid to a process chamber is initiated. Thetuning fluid flows through an input supply, a crossover network, and achamber supply before being dispensed within the process chamber.Operation 802 initiates fluid flow of process fluids to the processchamber. The process fluids are supplied to the process chamber throughan input supply, the crossover network, and the chamber supply.

In one embodiment, the chamber supply includes an edge supply and acenter supply that are both connected to the crossover network.Similarly, the input supply may include a plurality of supplies. Forexample, in one embodiment, the input supply has a first supply for thetuning fluid and a second supply for the process fluid. In thisembodiment, each of the respective supplies for the tuning fluid andprocess fluids are connected to the crossover network.

With operation 804, flow of both the tuning fluid and the process fluidis stopped. Operation 806 purges the input supply, the crossover networkand the chamber supply. Operation 808 flows one of either the processfluid or the tuning fluid to both the center supply and the edge supplythrough an open crossover valve within the crossover network. Thedescription of the preceding operations should be viewed as oneembodiment and should not be construed as limiting. For example, inanother embodiment, operation 800 can flow process fluid rather thantuning fluid. Similarly, operation 802 can flow tuning fluid rather thanprocess fluid. Additionally, in other embodiments, the purge operationcan include flowing of non-reactive fluids within the input supplies,the crossover network and the chamber supply. Such an operation can beused to minimize potential contamination from residual process or tuningfluid within a supply.

Although the foregoing invention has been described in some detail forpurposes of clarity of understanding, it will be apparent that certainchanges and modifications may be practiced within the scope of theappended claims. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the appended claims.

What is claimed is:
 1. An apparatus to supply a plurality of processfluids for processing a substrate in a semiconductor processing chamber,comprising: a fluid supply network being defined between a crossovervalve and a tuning supply valve and a plurality of process fluid supplyvalves; a tuning fluid supply being connected to the fluid supplynetwork through the tuning supply valve; a plurality of process fluidsbeing connected to the fluid supply network through the plurality ofprocess fluid supply valves; and a process chamber having a substratesupport, the process chamber further having an edge fluid supply and acenter fluid supply, the edge fluid supply connected to the fluid supplynetwork through an edge enable valve and the center supply connected tothe fluid supply network through a center enable valve; wherein thecrossover valve, edge enable valve, and center enable valve allow one oftuning fluid or process fluids to flow to one of the edge fluid supplyor the center fluid supply.
 2. An apparatus as described in claim 1,further comprising: a pumpout pump connected to the edge supply and thecenter supply through a respective edge pump valve and a center pumpvalve, wherein the pumpout pump evacuates fluid within the fluid supplynetwork.
 3. An apparatus as described in claim 1, further comprising: apurge pump connected to the fluid supply network through respective edgepurge valve and center purge valve, wherein the purge pump evacuatesfluid within the fluid supply network.
 4. An apparatus as described inclaim 1, wherein when the crossover valve is closed the tuning fluid isdirected to the center supply and the process fluid is directed to theedge fluid supply.
 5. A supply network to control fluid flow to aprocess chamber, comprising: a tuning fluid supply being coupled to aninput supply network through a tuning supply valve; a process fluidsupply being coupled to the input supply network through a processsupply valve; and a crossover network having a crossover valve, thecrossover network coupled between the input supply network and a processchamber having an edge supply and a center supply, the edge supplycoupled to the crossover network through an edge supply valve and thecenter supply coupled to the crossover network through a center fluidsupply valve; wherein the crossover valve defines whether the tuningfluid or the process fluid is supplied to one of the edge supply or thecenter supply.
 6. A supply network as described in claim 5, wherein whenthe crossover valve is closed the tuning fluid is directed to the centersupply and the process fluid is directed to the edge supply.
 7. A supplynetwork as described in claim 5, wherein the process fluid supply isdefined to support a plurality of process fluids.
 8. A supply network asdescribed in claim 5, further including an input purge system beingdefined between the input supply network and the crossover network.
 9. Asupply network as described in claim 8, wherein the input purge systemis defined to purge one or both of the tuning fluid and the processfluid.
 10. A supply network as described in claim 5, further including asupply purge being defined between the crossover network and the processchamber.
 11. A supply network as described in claim 10, wherein thesupply purge is defined to purge one or both of the tuning fluid and theprocess fluid.
 12. A supply network as described in claim 5, wherein thetuning fluid supply includes a filter being positioned proximate to theprocess chamber.
 13. A supply network as described in claim 5, whereinthe process fluid supply includes a filter being positioned proximate tothe process chamber.
 14. A method to provide flexible application of atuning fluid and a process fluid to a substrate, comprising: (a)enabling flow of the tuning fluid to a center supply through a firstsupply network, the first supply network coupled to a cross-flow networkthat includes a closed crossflow valve; (b) enabling flow of the processfluid to an edge supply through a second supply network, the secondsupply network coupled to the cross-flow network, the process fluidflowing to the edge supply; (c) disabling flow of the tuning fluid andthe process fluid; and (d) enabling flow of one of the tuning fluid orthe process fluid, wherein a open cross-flow valve routes the one of thetuning fluid or the process fluid to one of the center supply or theedge supply.
 15. A method as described in claim 14, further comprisingthe operation of purging at least one of the first supply network, thesecond supply network, the cross-flow network, the center supply and theedge supply through a purge network connected between the cross-flownetwork and the center supply and edge supply, the purging beingperformed between operations (c) and (d).
 16. A method as described inclaim 15, wherein purging includes the introduction of a purging fluid.17. A method as described in claim 16, wherein the purging fluid is thesame as the tuning fluid.
 18. A method as described in claim 16, whereinthe purging fluid is different than the tuning fluid.